* only change the window title if the new title is different from   the old one; updating is apparently an expensive op, and the   window mgr, gtk, etc. don't do this check themselves
* only change the window title if the new title is different from
  the old one; updating is apparently an expensive op, and the
  window mgr, gtk, etc. don't do this check themselves

pmo-trunk-r3937

community-ssu/modest,community-ssu/modest,community-ssu/modest,community-ssu/modest